VOA慢速英语:Researchers: Driverless Scooter Provides Safe and Easy Ride

scooter – n. small vehicle with a motor used for transportation

sensor – n. a device that can sense light, heat, sound, motion and provide information about it

off-the-shelf - adj. available from existing materials

seamless - adj. moving from one thing to another easily and without problems

relaxed - adj. feeling satisfied and comfortable